A few suggestions
First : I agree with others .One should not be alone while cutting trees,,,,,ESPECIALLY WHILE ALOFT.
But ,I must confess to my crime,as I have done it ,once or twice,so here are a few tips.
You say you are doing light rigging? One of my favorites is to tip the limb or log over with a rope with it secured with a running bowline,then secure the saw,then you will have use of both hands to slipoff or untie the rope and throw the piece to the desired area on the ground. A little bit slower than "cut-n -throw" with one hand on the saw and one on the piece,but a LOT safer.
If you are not real high in the tree,you can use both ends of the rigging line,and the other end of your climb line.this will get you 3 heavy pcs on the ground.
However ,do not use the other end of the C L if it will use so much rope that you can't reach the ground. ALWAYS be able to escape .